Clinical course and disease burden of RSV-infected hospitalized adults in Germany

<bold>Background:</bold> Respiratory syncytial virus (RSV) is a common cause of acute respiratory infections (ARI) and can lead to severe disease, especially in older adults. The clinical course of RSV-ARI in adults is not well described, especially in Europe. <bold>Methods:</bold> BUCOSS Hosp is a prospective, multicenter observational study including patients (> 18 years) hospitalized with ARI from 11 German hospitals. Comprehensive data on symptoms, comorbidities, complications, therapy and quality of life are collected from patients with a positive RSV PCR test result during their inpatient stay and over a follow-up period of 90 days after admission. Results are compared with patients hospitalized with a positive SARS-CoV-2 or influenza test. <bold>Results:</bold> 808 patients (84% > 50 years old) were recruited of whom 32 (4%) were tested positive for RSV, 96 (12%) for influenza and 98 (12%) for SARS-CoV-2. At least one comorbidity was present in 30 (94%) of RSV patients (influenza: 88%; SARS-CoV-2: 91%). A chronic lung disease was present in 20 of the RSV patients (63%) (influenza: 49%; SARS-CoV-2: 34%). Cough, purulent sputum, increased respiratory rate and rales were observed more frequently in RSV infections than in influenza or SARS-CoV-2 infections. The mean length of hospital stay was 8 days for RSV patients (influenza: 6 days; SARS-CoV-2: 7 days) with a higher probability of re-hospitalization for RSV patients (27%, influenza: 12%, SARS-CoV-2: 22%). <bold>Conclusion:</bold> The majority of patients hospitalized with RSV infection often have comorbidities, often present with severe symptoms, are hospitalized for a long time and are frequently re-hospitalized. Our findings provide an important contribution to understand ARI due to RSV infection.